Accelerate processor, efficient software and pervasive connections provide sensor nodes with more powerful computation and storage ability, which can offer various services to user. Based on these atomic services, dif...Accelerate processor, efficient software and pervasive connections provide sensor nodes with more powerful computation and storage ability, which can offer various services to user. Based on these atomic services, different sensor nodes can cooperate and compose with each other to complete more complicated tasks for user. However, because of the regional characteristic of sensor nodes, merging data with different sensitivities become a primary requirement to the composite services, and information flow security should be intensively considered during service composition. In order to mitigate the great cost caused by the complexity of modeling and the heavy load of single-node verification to the energy-limited sensor node, in this paper, we propose a new distributed verification framework to enforce information flow security on composite services of smart sensor network. We analyze the information flows in composite services and specify security constraints for each service participant. Then we propose an algorithm over the distributed verification framework involving each sensor node to participate in the composite service verification based on the security constraints. The experimental results indicate that our approach can reduce the cost of verification and provide a better load balance.展开更多
Wireless smart sensors(WSS)process field data and inform inspectors about the infrastructure health and safety.In bridge engineering,inspectors need reliable data about changes in displacements under loads to make cor...Wireless smart sensors(WSS)process field data and inform inspectors about the infrastructure health and safety.In bridge engineering,inspectors need reliable data about changes in displacements under loads to make correct decisions about repairs and replacements.Access to displacement information in the field and in real-time remains a challenge as inspectors do not see the data in real time.Displacement data from WSS in the field undergoes additional processing and is seen at a different location.If inspectors were able to see structural displacements in real-time at the locations of interest,they could conduct additional observations,creating a new,information-based,decision-making reality in the field.This paper develops a new,human-centered interface that provides inspectors with real-time access to actionable structural data during inspection and monitoring enhanced by augmented reality(AR).It summarizes and evaluates the development and validation of the new human-infrastructure interface in laboratory experiments.The experiments demonstrate that the interface that processes all calculations in the AR device accurately estimates dynamic displacements in comparison with the laser.Using this new AR interface tool,inspectors can observe and compare displacement data,share it across space and time,visualize displacements in time history,and understand structural deflection more accurately through a displacement time history visualization.展开更多
Conventional gas sensing materials(e.g.,metal oxides)suffer from deficient sensitivity and serve cross-sensitivity issues due to the lack of efficient adsorption sites.Herein,the heteroatom atomically doping strategy ...Conventional gas sensing materials(e.g.,metal oxides)suffer from deficient sensitivity and serve cross-sensitivity issues due to the lack of efficient adsorption sites.Herein,the heteroatom atomically doping strategy is demonstrated to significantly enhance the sensing performance of metal oxides-based gas sensing materials.Specifically,the Sn atoms were incorporated into porous Fe_(2)O_(3)in the form of atomically dispersed sites.As revealed by X-ray absorption spectroscopy and atomic-resolution scanning transmission electron microscopy,these Sn atoms successfully occupy the Fe sites in the Fe_(2)O_(3)lattice,forming the unique Sn-O-Fe sites.Compared to Fe-O-Fe sites(from bare Fe_(2)O_(3))and Sn-O-Sn sites(from SnO_(2)/Fe_(2)O_(3)with high Sn loading),the Sn-O-Fe sites on porous Fe_(2)O_(3)exhibit a superior sensitivity(Rg/Ra=2646.6)to 1 ppm NO_(2),along with dramatically increased selectivity and ultra-low limits of detection(10 ppb).Further theoretical calculations suggest that the strong adsorption of NO_(2)on Sn-O-Fe sites(N atom on Sn site,O atom on Fe site)contributes a more efficient gas response,compared to NO_(2)on Fe-O-Fe sites and other gases on Sn-O-Fe sites.Moreover,the incorporated Sn atoms reduce the bandgap of Fe_(2)O_(3),not only facilitating the electron release but also increasing the NO_(2)adsorption at a low working temperature(150°C).This work introduces an effective strategy to construct effective adsorption sites that show a unique response to specific gas molecules,potentially promoting the rational design of atomically modified gas sensing materials with high sensitivity and high selectivity.展开更多
The acetone-sensing properties of the undoped and Pd doped perovskite-type oxides NdFeO3 were investigated from room temperature to 400°C. The perovskite-type NdFeO3 was synthesized by a sol-gel method, and the d...The acetone-sensing properties of the undoped and Pd doped perovskite-type oxides NdFeO3 were investigated from room temperature to 400°C. The perovskite-type NdFeO3 was synthesized by a sol-gel method, and the dopants Pd with the content from 1wt% to 5wt% were implanted into NdFeO3 nanoparticles by thermal diffusion. X-ray diffraction （XRD） and scanning electron microscopy （SEM） techniques show that NdFeO3 is an orthorhombic structure with the average particle size of about 40 nm. A giant acetone-sensing response of 675.7 is observed when the Pd content in NdFeO3 powders is about 3wt%. The response and recovery time of the sensor to the 5×10–4 acetone gas are 16 and 1 s, respectively. At the same time, it performs a good selectivity to acetone gas and may be a new promising material candidate for the acetone-sensor development.展开更多
Mn doped SnO2 nanobelts (Mn:SnO2 NBs) and pure SnO2 nanobelts (SnO2 NBs) were synthesized by thermal evaporation technique at 1355°C with Ar carrier gas (25 sccm, 150 Torr). The SEM, EDS, XRD, TEM, HRTEM, SAED, X...Mn doped SnO2 nanobelts (Mn:SnO2 NBs) and pure SnO2 nanobelts (SnO2 NBs) were synthesized by thermal evaporation technique at 1355°C with Ar carrier gas (25 sccm, 150 Torr). The SEM, EDS, XRD, TEM, HRTEM, SAED, XPS, UV-Vis techniques were used to characterize the attained samples. The band gap of Mn doped SnO2 NBs by UV-Vis was measured to be 3.43 eV at room temperature, lower than that of the pure counterpart with ~3.66 eV. Mn:SnO2 NB and pure SnO2 NB sensors were developed. It is found that Mn:SnO2 NB device exhibits a higher sensitivity with 62.12% to 100 ppm of ethanol at 210°C, which is the highest sensitivity among the three tested VOC gases (ethanol, ethanediol, and acetone). The theoretical detection limit for ethanol of the sensor is 1.1 ppm. The higher response is related to the selective catalysis of the doped Mn ions.展开更多
Zinc Sulfide (ZnS) thin film has attracted increasing attention due to their potential applications in the new generation of nano-electronics and opto-electronics devices. The physical and chemical properties of ZnS h...Zinc Sulfide (ZnS) thin film has attracted increasing attention due to their potential applications in the new generation of nano-electronics and opto-electronics devices. The physical and chemical properties of ZnS have outstanding quality for different applications. Moreover, ZnS doped with various elements are creating a new era for both academic research and industrial applications. So, the optical properties of modified ZnS thin film will help us to find a suitable doping element for convenient deposition which may enhance the conductance and transmitting properties of the film. This review work has been carried out to explore the four-modification elements that constitute Cu, Ni, Co & Fe as descending order of atomic number corresponding to Zn, along with some potential applications considering the recent research work with other doping elements too such as Al, C, Pt etc. For example, FE, FET, Catalytic, Solar cell, Electroluminescence, Fuel cell, different sensors (Chemical sensors, Bio-sensors, Humidity sensors, light sensors, UV light sensors) and nanogenerators use ZnS thin film.展开更多
The recent resurgence of pneumoconiosis among coal miners in the United States has been linked to their exposure to excessive levels of coal dust.PDM3700 monitors are used in the mining industry to measure each miner&...The recent resurgence of pneumoconiosis among coal miners in the United States has been linked to their exposure to excessive levels of coal dust.PDM3700 monitors are used in the mining industry to measure each miner's coal dust exposure levels and control overexposure.However,the high cost of the PDM3700 hinders its use in measuring the exposure levels of all miners.Plantower PMS5003 low-cost particulate matter(PM)sensors can measure coal dust concentrations with high spatial resolution in real-time owing to their low cost and small size.However,these sensors require extensive calibration to ensure a high accuracy over long deployment periods.Because they have only been calibrated for mining-induced PM monitoring using linear regression models,the objective of this study was to leverage machine learning algorithms for calibration of coal-dust-monitoring sensors.Laboratory collocation tests were performed using the PDM3700 and aerodynamic particle sizer as reference monitors in a wind tunnel at a wide range of concentrations(0-3mg/m^(3)),temperatures(20-32℃),and relative humidities(23%-43%).The results revealed that nonlinear machine learning techniques significantly outperformed traditional linear regression models for low-cost sensor calibration.With the artificial neural network(ANN)being the strongest calibration model,Pearson's correlation of the PMS5003 sensors reached 0.98 and 0.97,those of the Airtrek sensors reached of 0.89 and 0.91,and those of the GasLab sensors reached 0.93 and 0.92.This shows a 2%-11%improvement in model performance over the linear regression model using ANN calibration.The success of the machine learning algorithms used in this study demonstrates the feasibility of deploying low-cost PM sensors for coal dust monitoring in mines.展开更多
Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,etc.With the development of sensor technology,wireless communication,smart...Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,etc.With the development of sensor technology,wireless communication,smart monitoring terminal,cloud storage/computing technology,and artificial intelligence,smart gas sensors represent the future of gassensing due to their merits of real-time multifunctional monitoring,earlywarning function,and intelligent and automated feature.Various electronicand optoelectronic gas sensors have been developed for high-performancesmart gas analysis.With the development of smart terminals and the maturityof integrated technology,flexible and wearable gas sensors play an increasingrole in gas analysis.This review highlights recent advances of smart gassensors in diverse applications.The structural components and fundamentalprinciples of electronic and optoelectronic gas sensors are described,andflexible and wearable gas sensor devices are highlighted.Moreover,sensorarray with artificial intelligence algorithms and smart gas sensors in“Internet of Things”paradigm are introduced.Finally,the challengesand perspectives of smart gas sensors are discussed regarding the future need of gas sensors for smart city and healthy living.展开更多
The proliferation of wearable biodevices has boosted the development of soft,innovative,and multifunctional materials for human health monitoring.The integration of wearable sensors with intelligent systems is an over...The proliferation of wearable biodevices has boosted the development of soft,innovative,and multifunctional materials for human health monitoring.The integration of wearable sensors with intelligent systems is an overwhelming tendency,providing powerful tools for remote health monitoring and personal health management.Among many candidates,two-dimensional(2D)materials stand out due to several exotic mechanical,electrical,optical,and chemical properties that can be efficiently integrated into atomic-thin films.While previous reviews on 2D materials for biodevices primarily focus on conventional configurations and materials like graphene,the rapid development of new 2D materials with exotic properties has opened up novel applications,particularly in smart interaction and integrated functionalities.This review aims to consolidate recent progress,highlight the unique advantages of 2D materials,and guide future research by discussing existing challenges and opportunities in applying 2D materials for smart wearable biodevices.We begin with an in-depth analysis of the advantages,sensing mechanisms,and potential applications of 2D materials in wearable biodevice fabrication.Following this,we systematically discuss state-of-the-art biodevices based on 2D materials for monitoring various physiological signals within the human body.Special attention is given to showcasing the integration of multi-functionality in 2D smart devices,mainly including self-power supply,integrated diagnosis/treatment,and human–machine interaction.Finally,the review concludes with a concise summary of existing challenges and prospective solutions concerning the utilization of2D materials for advanced biodevices.展开更多
The use of piezoelectric material sensors in smart composite structures is investigated. An experimental structure bonded with lead zirconate titanate piezoelectric ceramic(PZT) sensors is developed. These bonded sens...The use of piezoelectric material sensors in smart composite structures is investigated. An experimental structure bonded with lead zirconate titanate piezoelectric ceramic(PZT) sensors is developed. These bonded sensors are employed to monitor load variations and transient impacts in the structure. Incorporated with pattern recognition approach, PZT sensors have succeeded in detecting the onset and location of damages.展开更多
In the work of developing extrinsic fabry perot interferometric (EFPI), the key technology of polishing fiber optic endfaces and coating the multilayer of dielectric films on them is raised and resolved to settle the...In the work of developing extrinsic fabry perot interferometric (EFPI), the key technology of polishing fiber optic endfaces and coating the multilayer of dielectric films on them is raised and resolved to settle the disturbance and stability problem of EFPI, which simplifies the sensing system, improves the sensor performance and reduces the cost. In this paper, the relations between the output interferential light intensity and the F P cavity length are calculated based on the theory of mode field coupling. The EFPI fiber optic sensor is adhered to a distributed smart laminate beam to detect vibration frequency and axial strain value, the results coincident with the results tested by PZT.展开更多
The performances of two liquid level sensors based on long-period fiber gratings are studied. The long- period gratings （LPGs） have similar characteristics （length and period）, but are fabricated with two pho- tos...The performances of two liquid level sensors based on long-period fiber gratings are studied. The long- period gratings （LPGs） have similar characteristics （length and period）, but are fabricated with two pho- tosensitive B-Ge co-doped fibers with different dopant concentrations. We investigate the temperature sensitivities of LPGs and exploit their refractive index sensitivity to implement liquid level measurement. By controlling fiber parameters, such as the dopant concentrations, the measurement sensitivity of a LPG- based fiber optic liouid level sensor can be improved.展开更多
With the advance of smart material science,robotics is evolving from rigid robots to soft robots.Compared to rigid robots,soft robots can safely interact with the environment,easily navigate in unstructured fields,and...With the advance of smart material science,robotics is evolving from rigid robots to soft robots.Compared to rigid robots,soft robots can safely interact with the environment,easily navigate in unstructured fields,and be minimized to operate in narrow spaces,owning to the new actuation and sensing technologies developed by the smart materials.In the review,different actuation and sensing technologies based on different smart materials are analyzed and summarized.According to the driving or feedback signals,actuators are categorized into electrically responsive actuators,thermally responsive actuators,magnetically responsive actuators,and photoresponsive actuators;sensors are categorized into resistive sensors,capacitive sensors,magnetic sensors,and optical waveguide sensors.After introducing the principle and several robotic prototypes of some typical materials in each category of the actuators and sensors.The advantages and disadvantages of the actuators and sensors are compared based on the categories,and their potential applications in robotics are also presented.展开更多
Bimodal pressure sensors capable of simultaneously detecting static and dynamic forces are essential to medical detection and bio-robotics.However,conventional pressure sensors typically integrate multiple operating m...Bimodal pressure sensors capable of simultaneously detecting static and dynamic forces are essential to medical detection and bio-robotics.However,conventional pressure sensors typically integrate multiple operating mechanisms to achieve bimodal detection,leading to complex device architectures and challenges in signal decoupling.In this work,we address these limitations by leveraging the unique piezotronic effect of Y-ion-doped ZnO to develop a bimodal piezotronic sensor(BPS)with a simplified structure and enhanced sensitivity.Through a combination of finite element simulations and experimental validation,we demonstrate that the BPS can effectively monitor both dynamic and static forces,achieving an on/off ratio of 1029,a gauge factor of 23,439 and a static force response duration of up to 600 s,significantly outperforming the performance of conventional piezoelectric sensors.As a proof-of-concept,the BPS demonstrates the continuous monitoring of Achilles tendon behavior under mixed dynamic and static loading conditions.Aided by deep learning algorithms,the system achieves 96%accuracy in identifying Achilles tendon movement patterns,thus enabling warnings for dangerous movements.This work provides a viable strategy for bimodal force monitoring,highlighting its potential in wearable electronics.展开更多
We discuss blending sensor scheduling strategies with particle filtering (PF) methods to deal with the prob-lem of tracking a ‘smart’ target, that is, a target being able to be aware it is being tracked and act in a...We discuss blending sensor scheduling strategies with particle filtering (PF) methods to deal with the prob-lem of tracking a ‘smart’ target, that is, a target being able to be aware it is being tracked and act in a manner that makes the future track more difficult. We concern here how to accurately track the target with a care on concealing the observer to a possible extent. We propose a PF method, which is tailored to mix a sensor scheduling technique, called covariance control, within its framework. A Rao-blackwellised unscented Kal-man filter (UKF) is used to produce proposal distributions for the PF method, making it more robust and computationally efficient. We show that the proposed method can balance the tracking filter performance with the observer’s concealment.展开更多
The wireless sensor network （WSN） consists of sensor nodes that interact with each other to collectively monitor environmental or physical conditions at different locations for the intended users. One of its potenti...The wireless sensor network （WSN） consists of sensor nodes that interact with each other to collectively monitor environmental or physical conditions at different locations for the intended users. One of its potential deployments is in the form of smart home and ambient assisted living （SHAAL）to measure patients or elderly physiological signals, control home appliances, and monitor home. This paper focuses on the development of a wireless sensor node platform for SHAAL application over WSN which complies with the IEEE 802.15.4 standard and operates in 2.4 GHz ISM （industrial, scientific, and medical） band. The initial stage of SHAAL application development is the design of the wireless sensor node named TelG mote. The main features of TelG mote contributing to the green communications include low power consumption, wearable, flexible, user-friendly, and small sizes. It is then embedded with a self-built operating system named WiseOS to support customized operation. The node can achieve a packet reception rate （PRR） above 80% for a distance of up to 8 m. The designed TelG mote is also comparable with the existing wireless sensor nodes available in the market.展开更多
The battery technology progress has been a contradictory process in which performance improvement and hidden risks coexist.Now the battery is still a“black box”,thus requiring a deep understanding of its internal st...The battery technology progress has been a contradictory process in which performance improvement and hidden risks coexist.Now the battery is still a“black box”,thus requiring a deep understanding of its internal state.The battery should“sense its internal physical/chemical conditions”,which puts strict requirements on embedded sensing parts.This paper summarizes the application of advanced optical fiber sensors in lithium-ion batteries and energy storage technologies that may be mass deployed,focuses on the insights of advanced optical fiber sensors into the processes of one-dimensional nano-micro-level battery material structural phase transition,electrolyte degradation,electrode-electrolyte interface dynamics to three-dimensional macro-safety evolution.The paper contributes to understanding how to use optical fiber sensors to achieve“real”and“embedded”monitoring.Through the inherent advantages of the advanced optical fiber sensor,it helps clarify the battery internal state and reaction mechanism,aiding in the establishment of more detailed models.These advancements can promote the development of smart batteries,with significant importance lying in essentially promoting the improvement of system consistency.Furthermore,with the help of smart batteries in the future,the importance of consistency can be weakened or even eliminated.The application of advanced optical fiber sensors helps comprehensively improve the battery quality,reliability,and life.展开更多
Based on the advantages of the fiber Bragg grating sensing technology,this paper presents a principle of a novel smart concrete with fiber optical Bragg grating sensor,analyses the theory and characteristics,illustrat...Based on the advantages of the fiber Bragg grating sensing technology,this paper presents a principle of a novel smart concrete with fiber optical Bragg grating sensor,analyses the theory and characteristics,illustrates the key technology and method to make the fiber Bragg grating sensor for the smart concrete,and proves the feasibility with experiments.The results indicate that the smart concrete with fiber Bragg grating sensors is feasible in the structure monitoring and damage diagnosing in the long run.展开更多
基金supported in part by National Natural Science Foundation of China(61502368,61303033,U1135002 and U1405255)the National High Technology Research and Development Program(863 Program)of China(No.2015AA017203)+1 种基金the Fundamental Research Funds for the Central Universities(XJS14072,JB150308)the Aviation Science Foundation of China(No.2013ZC31003,20141931001)
文摘Accelerate processor, efficient software and pervasive connections provide sensor nodes with more powerful computation and storage ability, which can offer various services to user. Based on these atomic services, different sensor nodes can cooperate and compose with each other to complete more complicated tasks for user. However, because of the regional characteristic of sensor nodes, merging data with different sensitivities become a primary requirement to the composite services, and information flow security should be intensively considered during service composition. In order to mitigate the great cost caused by the complexity of modeling and the heavy load of single-node verification to the energy-limited sensor node, in this paper, we propose a new distributed verification framework to enforce information flow security on composite services of smart sensor network. We analyze the information flows in composite services and specify security constraints for each service participant. Then we propose an algorithm over the distributed verification framework involving each sensor node to participate in the composite service verification based on the security constraints. The experimental results indicate that our approach can reduce the cost of verification and provide a better load balance.
基金Air Force Research Laboratory(AFRL,Grant No.FA9453-18-2-0022)the New Mexico Consortium(NMC,Grant No.2RNA6)the US Department of Transportation Center:Transportation Consortium of South-Central States(TRANSET)Project 19STUNM02(TRANSET,Grant No.8-18-060ST)。
文摘Wireless smart sensors(WSS)process field data and inform inspectors about the infrastructure health and safety.In bridge engineering,inspectors need reliable data about changes in displacements under loads to make correct decisions about repairs and replacements.Access to displacement information in the field and in real-time remains a challenge as inspectors do not see the data in real time.Displacement data from WSS in the field undergoes additional processing and is seen at a different location.If inspectors were able to see structural displacements in real-time at the locations of interest,they could conduct additional observations,creating a new,information-based,decision-making reality in the field.This paper develops a new,human-centered interface that provides inspectors with real-time access to actionable structural data during inspection and monitoring enhanced by augmented reality(AR).It summarizes and evaluates the development and validation of the new human-infrastructure interface in laboratory experiments.The experiments demonstrate that the interface that processes all calculations in the AR device accurately estimates dynamic displacements in comparison with the laser.Using this new AR interface tool,inspectors can observe and compare displacement data,share it across space and time,visualize displacements in time history,and understand structural deflection more accurately through a displacement time history visualization.
基金supported by the National Key Research and Development Project of China(Grant No.2022YFB3205500)the National Natural Science Foundation of China(Grant No.12275190,12105201)+2 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2024ZB723)the Shenzhen Research Funding Program(JCYJ20230807154402004)supported by the Collaborative Innovation Center of Suzhou Nano Science&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),the 111 Project,the Joint International Research Laboratory of Carbon-Based Functional Materials and Devices,and the Suzhou Key Laboratory of Functional Nano&Soft Materials and Soochow University-Western University Centre for Synchrotron Radiation Research.
文摘Conventional gas sensing materials(e.g.,metal oxides)suffer from deficient sensitivity and serve cross-sensitivity issues due to the lack of efficient adsorption sites.Herein,the heteroatom atomically doping strategy is demonstrated to significantly enhance the sensing performance of metal oxides-based gas sensing materials.Specifically,the Sn atoms were incorporated into porous Fe_(2)O_(3)in the form of atomically dispersed sites.As revealed by X-ray absorption spectroscopy and atomic-resolution scanning transmission electron microscopy,these Sn atoms successfully occupy the Fe sites in the Fe_(2)O_(3)lattice,forming the unique Sn-O-Fe sites.Compared to Fe-O-Fe sites(from bare Fe_(2)O_(3))and Sn-O-Sn sites(from SnO_(2)/Fe_(2)O_(3)with high Sn loading),the Sn-O-Fe sites on porous Fe_(2)O_(3)exhibit a superior sensitivity(Rg/Ra=2646.6)to 1 ppm NO_(2),along with dramatically increased selectivity and ultra-low limits of detection(10 ppb).Further theoretical calculations suggest that the strong adsorption of NO_(2)on Sn-O-Fe sites(N atom on Sn site,O atom on Fe site)contributes a more efficient gas response,compared to NO_(2)on Fe-O-Fe sites and other gases on Sn-O-Fe sites.Moreover,the incorporated Sn atoms reduce the bandgap of Fe_(2)O_(3),not only facilitating the electron release but also increasing the NO_(2)adsorption at a low working temperature(150°C).This work introduces an effective strategy to construct effective adsorption sites that show a unique response to specific gas molecules,potentially promoting the rational design of atomically modified gas sensing materials with high sensitivity and high selectivity.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50872069 and 50872074)
文摘The acetone-sensing properties of the undoped and Pd doped perovskite-type oxides NdFeO3 were investigated from room temperature to 400°C. The perovskite-type NdFeO3 was synthesized by a sol-gel method, and the dopants Pd with the content from 1wt% to 5wt% were implanted into NdFeO3 nanoparticles by thermal diffusion. X-ray diffraction （XRD） and scanning electron microscopy （SEM） techniques show that NdFeO3 is an orthorhombic structure with the average particle size of about 40 nm. A giant acetone-sensing response of 675.7 is observed when the Pd content in NdFeO3 powders is about 3wt%. The response and recovery time of the sensor to the 5×10–4 acetone gas are 16 and 1 s, respectively. At the same time, it performs a good selectivity to acetone gas and may be a new promising material candidate for the acetone-sensor development.
文摘Mn doped SnO2 nanobelts (Mn:SnO2 NBs) and pure SnO2 nanobelts (SnO2 NBs) were synthesized by thermal evaporation technique at 1355°C with Ar carrier gas (25 sccm, 150 Torr). The SEM, EDS, XRD, TEM, HRTEM, SAED, XPS, UV-Vis techniques were used to characterize the attained samples. The band gap of Mn doped SnO2 NBs by UV-Vis was measured to be 3.43 eV at room temperature, lower than that of the pure counterpart with ~3.66 eV. Mn:SnO2 NB and pure SnO2 NB sensors were developed. It is found that Mn:SnO2 NB device exhibits a higher sensitivity with 62.12% to 100 ppm of ethanol at 210°C, which is the highest sensitivity among the three tested VOC gases (ethanol, ethanediol, and acetone). The theoretical detection limit for ethanol of the sensor is 1.1 ppm. The higher response is related to the selective catalysis of the doped Mn ions.
文摘Zinc Sulfide (ZnS) thin film has attracted increasing attention due to their potential applications in the new generation of nano-electronics and opto-electronics devices. The physical and chemical properties of ZnS have outstanding quality for different applications. Moreover, ZnS doped with various elements are creating a new era for both academic research and industrial applications. So, the optical properties of modified ZnS thin film will help us to find a suitable doping element for convenient deposition which may enhance the conductance and transmitting properties of the film. This review work has been carried out to explore the four-modification elements that constitute Cu, Ni, Co & Fe as descending order of atomic number corresponding to Zn, along with some potential applications considering the recent research work with other doping elements too such as Al, C, Pt etc. For example, FE, FET, Catalytic, Solar cell, Electroluminescence, Fuel cell, different sensors (Chemical sensors, Bio-sensors, Humidity sensors, light sensors, UV light sensors) and nanogenerators use ZnS thin film.
基金funded by the National Science Foundation(No.2034198)the National Institute for Occupational Safety and Health(NIOSH)(No.75D30123C17714)
文摘The recent resurgence of pneumoconiosis among coal miners in the United States has been linked to their exposure to excessive levels of coal dust.PDM3700 monitors are used in the mining industry to measure each miner's coal dust exposure levels and control overexposure.However,the high cost of the PDM3700 hinders its use in measuring the exposure levels of all miners.Plantower PMS5003 low-cost particulate matter(PM)sensors can measure coal dust concentrations with high spatial resolution in real-time owing to their low cost and small size.However,these sensors require extensive calibration to ensure a high accuracy over long deployment periods.Because they have only been calibrated for mining-induced PM monitoring using linear regression models,the objective of this study was to leverage machine learning algorithms for calibration of coal-dust-monitoring sensors.Laboratory collocation tests were performed using the PDM3700 and aerodynamic particle sizer as reference monitors in a wind tunnel at a wide range of concentrations(0-3mg/m^(3)),temperatures(20-32℃),and relative humidities(23%-43%).The results revealed that nonlinear machine learning techniques significantly outperformed traditional linear regression models for low-cost sensor calibration.With the artificial neural network(ANN)being the strongest calibration model,Pearson's correlation of the PMS5003 sensors reached 0.98 and 0.97,those of the Airtrek sensors reached of 0.89 and 0.91,and those of the GasLab sensors reached 0.93 and 0.92.This shows a 2%-11%improvement in model performance over the linear regression model using ANN calibration.The success of the machine learning algorithms used in this study demonstrates the feasibility of deploying low-cost PM sensors for coal dust monitoring in mines.
基金supported by the National Natural Science Foundation of China(No.22376159)the Fundamental Research Funds for the Central Universities.
文摘Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,etc.With the development of sensor technology,wireless communication,smart monitoring terminal,cloud storage/computing technology,and artificial intelligence,smart gas sensors represent the future of gassensing due to their merits of real-time multifunctional monitoring,earlywarning function,and intelligent and automated feature.Various electronicand optoelectronic gas sensors have been developed for high-performancesmart gas analysis.With the development of smart terminals and the maturityof integrated technology,flexible and wearable gas sensors play an increasingrole in gas analysis.This review highlights recent advances of smart gassensors in diverse applications.The structural components and fundamentalprinciples of electronic and optoelectronic gas sensors are described,andflexible and wearable gas sensor devices are highlighted.Moreover,sensorarray with artificial intelligence algorithms and smart gas sensors in“Internet of Things”paradigm are introduced.Finally,the challengesand perspectives of smart gas sensors are discussed regarding the future need of gas sensors for smart city and healthy living.
基金the support from the National Natural Science Foundation of China(22272004,62272041)the Fundamental Research Funds for the Central Universities(YWF-22-L-1256)+1 种基金the National Key R&D Program of China(2023YFC3402600)the Beijing Institute of Technology Research Fund Program for Young Scholars(No.1870011182126)。
文摘The proliferation of wearable biodevices has boosted the development of soft,innovative,and multifunctional materials for human health monitoring.The integration of wearable sensors with intelligent systems is an overwhelming tendency,providing powerful tools for remote health monitoring and personal health management.Among many candidates,two-dimensional(2D)materials stand out due to several exotic mechanical,electrical,optical,and chemical properties that can be efficiently integrated into atomic-thin films.While previous reviews on 2D materials for biodevices primarily focus on conventional configurations and materials like graphene,the rapid development of new 2D materials with exotic properties has opened up novel applications,particularly in smart interaction and integrated functionalities.This review aims to consolidate recent progress,highlight the unique advantages of 2D materials,and guide future research by discussing existing challenges and opportunities in applying 2D materials for smart wearable biodevices.We begin with an in-depth analysis of the advantages,sensing mechanisms,and potential applications of 2D materials in wearable biodevice fabrication.Following this,we systematically discuss state-of-the-art biodevices based on 2D materials for monitoring various physiological signals within the human body.Special attention is given to showcasing the integration of multi-functionality in 2D smart devices,mainly including self-power supply,integrated diagnosis/treatment,and human–machine interaction.Finally,the review concludes with a concise summary of existing challenges and prospective solutions concerning the utilization of2D materials for advanced biodevices.
文摘The use of piezoelectric material sensors in smart composite structures is investigated. An experimental structure bonded with lead zirconate titanate piezoelectric ceramic(PZT) sensors is developed. These bonded sensors are employed to monitor load variations and transient impacts in the structure. Incorporated with pattern recognition approach, PZT sensors have succeeded in detecting the onset and location of damages.
文摘In the work of developing extrinsic fabry perot interferometric (EFPI), the key technology of polishing fiber optic endfaces and coating the multilayer of dielectric films on them is raised and resolved to settle the disturbance and stability problem of EFPI, which simplifies the sensing system, improves the sensor performance and reduces the cost. In this paper, the relations between the output interferential light intensity and the F P cavity length are calculated based on the theory of mode field coupling. The EFPI fiber optic sensor is adhered to a distributed smart laminate beam to detect vibration frequency and axial strain value, the results coincident with the results tested by PZT.
基金supported by the National Natural Science Foundation of China under Grant No. 60907020
文摘The performances of two liquid level sensors based on long-period fiber gratings are studied. The long- period gratings （LPGs） have similar characteristics （length and period）, but are fabricated with two pho- tosensitive B-Ge co-doped fibers with different dopant concentrations. We investigate the temperature sensitivities of LPGs and exploit their refractive index sensitivity to implement liquid level measurement. By controlling fiber parameters, such as the dopant concentrations, the measurement sensitivity of a LPG- based fiber optic liouid level sensor can be improved.
基金Supported by National Key Research and Development Program of China(Grant No.2019YFB 1309800)National Natural Science Foundation of China(Grant Nos.62173197,91848206)Beijing Science&Technology Project(Grant No.Z191100008019008).
文摘With the advance of smart material science,robotics is evolving from rigid robots to soft robots.Compared to rigid robots,soft robots can safely interact with the environment,easily navigate in unstructured fields,and be minimized to operate in narrow spaces,owning to the new actuation and sensing technologies developed by the smart materials.In the review,different actuation and sensing technologies based on different smart materials are analyzed and summarized.According to the driving or feedback signals,actuators are categorized into electrically responsive actuators,thermally responsive actuators,magnetically responsive actuators,and photoresponsive actuators;sensors are categorized into resistive sensors,capacitive sensors,magnetic sensors,and optical waveguide sensors.After introducing the principle and several robotic prototypes of some typical materials in each category of the actuators and sensors.The advantages and disadvantages of the actuators and sensors are compared based on the categories,and their potential applications in robotics are also presented.
基金financially supported by the National Natural Science Foundation of China(No.U2330120)the Natural Science Foundation of Sichuan Province of China(No.2023NSFSC0313)the Basic Research Cultivation Project of Southwest Jiaotong University(No.2682023KJ024)。
文摘Bimodal pressure sensors capable of simultaneously detecting static and dynamic forces are essential to medical detection and bio-robotics.However,conventional pressure sensors typically integrate multiple operating mechanisms to achieve bimodal detection,leading to complex device architectures and challenges in signal decoupling.In this work,we address these limitations by leveraging the unique piezotronic effect of Y-ion-doped ZnO to develop a bimodal piezotronic sensor(BPS)with a simplified structure and enhanced sensitivity.Through a combination of finite element simulations and experimental validation,we demonstrate that the BPS can effectively monitor both dynamic and static forces,achieving an on/off ratio of 1029,a gauge factor of 23,439 and a static force response duration of up to 600 s,significantly outperforming the performance of conventional piezoelectric sensors.As a proof-of-concept,the BPS demonstrates the continuous monitoring of Achilles tendon behavior under mixed dynamic and static loading conditions.Aided by deep learning algorithms,the system achieves 96%accuracy in identifying Achilles tendon movement patterns,thus enabling warnings for dangerous movements.This work provides a viable strategy for bimodal force monitoring,highlighting its potential in wearable electronics.
文摘We discuss blending sensor scheduling strategies with particle filtering (PF) methods to deal with the prob-lem of tracking a ‘smart’ target, that is, a target being able to be aware it is being tracked and act in a manner that makes the future track more difficult. We concern here how to accurately track the target with a care on concealing the observer to a possible extent. We propose a PF method, which is tailored to mix a sensor scheduling technique, called covariance control, within its framework. A Rao-blackwellised unscented Kal-man filter (UKF) is used to produce proposal distributions for the PF method, making it more robust and computationally efficient. We show that the proposed method can balance the tracking filter performance with the observer’s concealment.
基金supported by the Ministry of Higher Education,Malaysia under Grant No.R.J130000.7823.4L626
文摘The wireless sensor network （WSN） consists of sensor nodes that interact with each other to collectively monitor environmental or physical conditions at different locations for the intended users. One of its potential deployments is in the form of smart home and ambient assisted living （SHAAL）to measure patients or elderly physiological signals, control home appliances, and monitor home. This paper focuses on the development of a wireless sensor node platform for SHAAL application over WSN which complies with the IEEE 802.15.4 standard and operates in 2.4 GHz ISM （industrial, scientific, and medical） band. The initial stage of SHAAL application development is the design of the wireless sensor node named TelG mote. The main features of TelG mote contributing to the green communications include low power consumption, wearable, flexible, user-friendly, and small sizes. It is then embedded with a self-built operating system named WiseOS to support customized operation. The node can achieve a packet reception rate （PRR） above 80% for a distance of up to 8 m. The designed TelG mote is also comparable with the existing wireless sensor nodes available in the market.
基金the National Natural Science Foundation of China(No.52307245[Y.D.Li],No.U21A20170[X.He],22279070[L.Wang],and 52206263[Y.Song])the China Postdoctoral Science Foundation(No.2022M721820[Y.D.Li])the Ministry of Science and Technology of China(No.2019YFA0705703[L.Wang])。
文摘The battery technology progress has been a contradictory process in which performance improvement and hidden risks coexist.Now the battery is still a“black box”,thus requiring a deep understanding of its internal state.The battery should“sense its internal physical/chemical conditions”,which puts strict requirements on embedded sensing parts.This paper summarizes the application of advanced optical fiber sensors in lithium-ion batteries and energy storage technologies that may be mass deployed,focuses on the insights of advanced optical fiber sensors into the processes of one-dimensional nano-micro-level battery material structural phase transition,electrolyte degradation,electrode-electrolyte interface dynamics to three-dimensional macro-safety evolution.The paper contributes to understanding how to use optical fiber sensors to achieve“real”and“embedded”monitoring.Through the inherent advantages of the advanced optical fiber sensor,it helps clarify the battery internal state and reaction mechanism,aiding in the establishment of more detailed models.These advancements can promote the development of smart batteries,with significant importance lying in essentially promoting the improvement of system consistency.Furthermore,with the help of smart batteries in the future,the importance of consistency can be weakened or even eliminated.The application of advanced optical fiber sensors helps comprehensively improve the battery quality,reliability,and life.
文摘Based on the advantages of the fiber Bragg grating sensing technology,this paper presents a principle of a novel smart concrete with fiber optical Bragg grating sensor,analyses the theory and characteristics,illustrates the key technology and method to make the fiber Bragg grating sensor for the smart concrete,and proves the feasibility with experiments.The results indicate that the smart concrete with fiber Bragg grating sensors is feasible in the structure monitoring and damage diagnosing in the long run.
